Your city has completely changed. We’re writing 2050, and you’re looking out the window. Between the buildings are fens and lakes. The noise of the traffic that once filled the streets has died down. And the distant suburbs have given way to forest.
You may well shed a tear at the loss of your parental home, but it really couldn’t have been otherwise.
This is what reality may look like for a large part of the world’s population in a few decades.
Today, 55 percent of Earth’s 8 billion inhabitants live in cities. By 2050, according to the UN, that will be 68 percent – and cities will be home to 2.5 billion more inhabitants than today.
This presents us with challenges, because living conditions in the cities deteriorate as it rains more, gets warmer and the sea level rises due to climate change.
But it also creates opportunities. Larger, more populous cities might make you think of more pollution, but it doesn’t have to be. In fact, the cities of the future offer us a golden opportunity to repair the damage we have done to the planet.
Cities struggle with heat
The temperature is rising, and especially in the city, according to a UN report from 2022.
The report describes how cities have been exposed to the heat island effect, which could cause it to become 2°C warmer on top of the 4-5°C temperature increase we already expect before 2100 due to global warming.
The heat island effect arises because asphalt absorbs the sun’s heat. At the same time, the wind cannot discharge the hot air on the leeward side of buildings.
Climate change is also bringing more rain, especially in cities. Tall buildings amplify the turbulence in the skies that generate the heaviest storms. And tiles, concrete and asphalt prevent water from running off.
The water can only escape through the sewer system, which is often not big enough to store a lot of it, resulting in devastating floods.
But the problems of heat and water can be solved with a simple measure: building parks.
In a 2021 Chinese study, scientists found that the parks in the city of Wuhan were cooler than the built-up areas. In some places the temperature difference was more than 7 °C.
Strategically placed green zones can thus help cool cities. Rainwater also flows better through it, so that we prevent flooding.
In parks, the large amount of rainwater can even be used to increase the cooling effect – ponds lower the temperature even further, according to the Wuhan study.
The cooling effect of parks does not only benefit the public space. In homes and offices, vertical facade gardens can lower the temperature indoors by as much as 4 °C.
An additional advantage is that gardens purify the air from, among other things, nitrogen compounds from exhaust gases.
Everyone can do anything
However, pollution from cars will be less of a problem in the future, if it’s up to the scientists. Fossil fuels such as diesel and petrol will gradually disappear from the cities.
The aim is not only to improve air quality, but also to reduce greenhouse gas emissions.
A major step towards lower emissions is to reduce the need for transport. Cities should be designed in such a way that all daily activities, such as work, shopping, health care, education and leisure, can be done with a maximum of 15 minutes on foot.
At the same time, the suburbs have to leave, because the transport distances are longer due to their widely spread buildings.
When people from suburbs come to live close together in the city, they travel shorter distances. At the same time, the surfaces of the suburbs are being freed up for the growth of forests, which can remove greenhouse gases from the air.
Electric car stores energy
The transport that is still there must run on green energy. The switch to electric transport is already underway. In Norway, for example, in 2021, 64.5 percent of new passenger cars were electric.
Not only do they emit less carbon dioxide than petrol cars, they also play another major role in the cities of the future: they can store energy from sun and wind and transfer it to the grid.
At the moment we cannot make do with the energy from wind or sun. It’s too fickle – power production depends on the weather and time of day.
But if we can store the surplus energy from sun and wind and use it when there is a shortage of green energy, we can get rid of fossil fuels completely.
However, the cities of the future must not only store green energy, but also generate it themselves.
The best high-voltage cables lose at least 0.5 percent and often much more of their energy for every 100 kilometers of cable, so the closer to the consumer the power is generated, the better.
That is why architects are already designing buildings with wind turbines on roofs, solar cells as facade cladding and windows and other integrated energy solutions.
Cities also need to become self-sufficient in another area: food. By growing vegetables in cities, we are left with agricultural land, which can then become wild.
At the same time, the products are already close to the consumer, which means we save on transport – and get fresher vegetables.
Lettuce comes from the cellar
In a 2020 US study, researchers looked at the climate costs of transporting fruit and vegetables.
The figures vary according to whether transport is by air, sea, truck or rail, but the trend is clear. If you bring 1 kilo of oranges from California to New York, you emit 0.3 kilo of CO2 from. If the oranges come from Mexico, that figure rises to 0.7 kilos of CO2.
The biggest profit comes from vegetables. Lettuce, for example, does not have to be grown on the land – this can also be done in floors in a former parking garage, using LED lamps.
Lettuce grown in the city with green energy and a lot of attention for the recycling of raw materials, emits only 0.16 kilos of CO2 per kilo, according to a study from 2018. By comparison: lettuce from the country produces 0.54 kilos of CO2 per kilo, of which 0.36 kilo comes from transport.
At the same time, urban vegetables require 80 to 90 percent less water and 95 percent less space.
Finnish city shows it off
Many of the technologies that could make the cities of the future climate neutral already exist. Yet no city is using them all yet.
But some cities are approaching the vision of the future. An example is the Finnish Kalasatama neighborhood in Helsinki. Here is a plan ready to make the area carbon neutral by 2040, while housing 30,000 people.
To this end, urban planners want to stimulate a development in which city dwellers can reach all daily amenities within walking distance.
Kalasatama is also built with a waste system without garbage trucks. The residents separate the waste and throw it into a chute, which leads to recycling or energy recovery.
Kalasatama is far from finished with his plan, but the project doesn’t have to be successful on the first try, either. Rather, the district serves as a testing ground for new green technologies.
If successful, the plan could be rolled out all over Helsinki and perhaps the rest of the world – and in the future, in the city where you live.